Attachment for pianos



(No ModeL) 2 Sheets-Sheet 1'.

P. W. HA

} ATTACHMENT PO NOS. I No. 896,156. Patented Jan. 15, 1889.

UNITED STATES PATENT OFFICE.

FRANCIS IV. HALE, OF BOSTON, MASSAGHL SETTS.

ATTACHMENT FOP? PlANOS.

SPECIFICATION forming part of Letters Patent No. 396,156, dated January 15, 1889 Application filed June 27, 1888.

To all whom it may c07zcc7'n:

Be'it known that I, FRANCIS W. HALE, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Attachments for Piano- Fortes, of which the following, taken in connection with the accompanying drawings, is a specification.

My invention relates to a device for detecting by an electric signal errors in the relative time of striking the keys, the object being to provide a means by which any error occurl ring in the relative time of depressing the keys will be indicated by a bell or other signal. This object I attain by the mechanism shown in the accompanying drawings, in which Figure 1 is a view showing in cross vertical section a portion of a piano and of my device attached. Fig. 2 is a view, partly in front elevation and partly in longitudinal vertical section, of parts of a piano and of my device. Figs. 3 and l are details. Fig. 5 is a view showing in cross vertical section a portion of a piano and a part of my device as modified, and Fig. 6 shows in front elevation a portion of the modified device.

Before explaining my invention it may be well for me to call attention to the fact that in the performance of a perfect legato upon the piano-forte itis absolutely necessary that the second string be set in vibration at the instant the first ceases. A tailu re to perform this condition arises from either one of the following causes, viz: Either the first key is raised and the tone dumped before the second is in vibration, thus giving the effect of what is technically called staccato, or the first key is held down until after the second string is in vibration, thus overlapping and causing the unsatisfactory effect known as lagging. In a former invention, application, Serial No. 273,100, I have arranged a bellsignal to indicate the presence of the first conditioni. e, st-accat0and in my present invention I have arranged a bell-signal to indicate the presence of the second condition27. e., overlappin The same device is furthermore a perfect indicatorof rugged chord or arpeggio practice, as I will presently explain.

In the drawings, B, Fig. 1, represents the Serial No. 278,368. No model.)

key of a piano-forte, the depression of which gives motion to the sticker D, which, extending through the key-frame A, in turn gives motion to the lever E, said lever E being pivoted at E and supported by the flange E which flange is fastened to the rail F.

H. Figs. 1, 2, 3, and l, represents thin strips of metal, each being attached to one of the levers E, and all connected by a wire, 0 C, to one of the platesthe carbon, for instance of an electric battery, L, Fig. 2.

G is a rail suspended by the cord G.

H H are metal points connected with the opposite pole to that of C-the Zinc, for i11- stance.

G, Figs. 1, 2, 3, and i, represents a rail suspended by cords G, so as to be free to swing longitudinally, and having upon it two sets of metal contact-points, one set being represented by H H and the other by K K. All of the points H are connected by the wire Z Z*, Figs. 2, 3, and 4, to the zinc pole of the battery, the line running through the electromagnetG (SeeFigzE. The otherset, K K, of contact-points are connected by a wire, Z, to an arm, K, on the swinging rail G, and through that arm (when the rail G is in the position indicated in Fig. l) to the stationary pin K thence through the wire Z to the bell M, and thence by the wire Z to the wire Z and to the zinc pole of the battery L.

' Figs. 2, 3, and st, represents the armature of the electro-magnet G, and is rigidly attached to the swinging rail G, so that when the electro-magnet G is charged it will draw the armature G onto it, and thus swing the rail G into the position shown in Fig. lthat is, in such a position that all of the contactpoints K K will be in position to connect (electrically) with the spring-strips H II on the lovers E E.

It will be observed that when the swinging rail G is in the position indicated in Fig. 4-,

I and two or more keysthc first and third,

for instanceare remaining down, (having been depressed at different times,) then there will be a divided current from the Zinc pole of the battery and buta single one to the carbon pole.

The act-ion of my device may be explained as follows The normal position of the rail G is such as to bring the point II, Fig. 2, under the metal contact-strips H II. If, now, one of the levers E be depressed so that the metal strip H comes in contact with the point II, the circuit will close, and the armature G which is fastened to the end of the rail G, will be drawn toward the electro-magnet G, thus closing the switch K K Figs. 2 and 4, and bringing the points K K into the position previously held by II. (See Fig. I.) If while in this position any otherof the levers E E be depressed, its metal strip II will connect with one of the points K K, as at H Fig. 4, and close the bell-circuit Z 'JZ". The bell, being a multiple stroke, will continue to sound until the switch-connection is broken at K K In actual practice the instrument is so regulated that if the performer is executing a perfect legato the bell-circuit will never be closed, and which is accomplished by relieving the first key before the second has descended far enough to bring the strip H, Fig. 2, in contact with the point K of the bell-line. This may be regulated at any point of the keys descent, according to the ideas of the performer.

As a monitor for chord or double-scale practice it is now evident that if any number of levers are depressed at the same instant the strips II will all fall on the one line of points H, Fig. 2; but as the bell-line can only close by closing both the magnet and bell currents no stroke will be made by the bell; but if any one of a series of notes is struck after another is down the bell-circuit will be closed and the bell sounded.

In Figs. 5 and 6 I have shown a modification of my device, which I will now explain. The rail g is hung on pivots, one of which is shown at P, Figs. 5 and 6, so that it can turn on its longitudinal axis from the position indicated by full lines in Fig. 5 to the position indicated by dotted lines. To the end of the rail g, I attach an armature, g which is also hung on the pivot P, and is arranged to oscillate, as indicated by dotted lines. One end, g, of the armature g is made heavier than the other, so as to hold it and the rail g in the position indicated by full lines in Figs. 5 and 6. N, Fig. 5, is a fixed stud which serves as a rest for the heavy end of the armature. \Yhen the electro-magnet G is charged, the armature g is drawn up to a horizontal position,

as indicated by dotted lines, and the rail g is turned more'to the left. (See dotted lines in Fig 5.) On one side of the rail g, I place the metal plate 71, which is electrically connected with a wire passing through the electro-magnet G to the Zinc pole of the battery, and on the other side of the rail g, I have a plate, 7;, which is electrically connected with a wire passin through a bell, (not shown,) also to the zinc pole of the battery. The metal strips h, attached to the levers E, Fig. 5, are all attached by a wire, I, to the carbon pole of the battery.

The normal position of the rail is such that when the lever is depressed the metal strip h falls upon that side of the rail to which is fastened the magnet line-wire, thus closing the circuit. The armature is so arranged that when the magnet-circuit is closed it will rotate the rail g, so that the edge of the rail is brought into the position shown in dotted lines, Fig. 5. If, now, any other lever is depressed, the metal strip will falhupon the other side, 7r, of the rail g and close the electrical connection of the bell-line, thus causing a continuous alarm until one be relieved. If, however, the first lever be relieved before the belllineis closed in any succeeding lever, no stroke will be given.

By combining the present device with my previous invention I am able to reduce the practice of musical students to a point where absolute certainty as to the character of work being done is made positively evident and their progress greatly facilitated.

I claim- In connection with a piano-forte action, the combination. of the stickers D and levers E, having metallic strips H electrically connected to one pole of a battery, with the movable rail G, adapted to be moved by magnetic action, and having upon it electric contact points or plates (electrically connected to a battery) adapted to be presented automatically in turn to the strips II, and an electricallyconnected bell or other signal divice, operatin g substantially as described, and for the purpose set forth.

FRANCIS IV. HALE.

'itnesses:

FRANK G. PARKER, IVILLIAM EDSON. 

